Implantable medical devices, such as catheters, guidewires, stents, etc. are widely used in procedures ranging from diagnostic evaluations to angioplasty, deployment of stents in the coronary arteries, and other medical procedures. During such procedures, a practitioner may need to know the position of the medical device during its positioning in a patient's body. For this purpose, a radiopaque material is sometimes affixed on the surface or incorporated in the material of the implantable medical device.
Using techniques such as fluoroscopy, real-time images of the location or orientation of medical devices in a patient body can be viewed or obtained using X-rays. To obtain bright and clear real-time images, the radiopaque material must have sufficient radiopacity, e.g., the ability of the material to absorb X-rays or high attenuation of X-ray energy to produce a high contrast fluoroscopic image. Thus, a device with a radiopaque material exhibits high attenuation of X-ray energy and can be seen with high contrast in the fluoroscopic image of the device. The radiopacity of a material depends on its composition.